Again, I'm guessing because I don't know, but I believe the lack of action is more related to perhaps a lowered budget rather than a directive for content, especially since after the middle of S, the attacks of the monsters of the day were much less violent. Most of SuperS's fights were very comedic, for instance.
However, after SuperS didn't bring in the ratings, I'm guessing the animation budget was cut. Given that there was also the 6-episode Nehellenia arc that did have action, it's likely corners had to be cut in the remaining episodes.